J.P. Instruments EDM 900 Pilots Guide - Manual (Page 34)

Page 34 Engine Data Management
Start Up Fuel
On power-up, you will be prompted to enter any fuel you might have
added to the aircraft (this process updates the REM and USD values).
The EDM will flash REFUEL? . If you didn’t add any fuel, simply tap NO
to quit, otherwise tap YES to pick one of the three quickset choices
below:
If you say YES then you will see Fuel onboard, if you have Aux tanks
you will see TWO chooses like in the example 76 GAL Main and Main +
Aux = 96GAL. You pick the one you want to enter.
Upon making a choice you will see your choice as Initial Fuel
If you tap ADD SUBTRACT then you can add say 10 gallons
NOTE: If you forgot to perform your EDM REFUEL before starting
the engine, it can still be performed. The EDM will automatically
subtract any burned fuel from the value you choose. Go to Program
mode and the first item is REFUEL
You are responsible for insuring that your usage of the REFUEL
feature results in the EDM’s REM parameter showing the correct
amount of usable fuel remaining onboard the aircraft.